static void
lower_load_sample_pos(lower_wpos_ytransform_state *state,
nir_intrinsic_instr *intr)
{
nir_builder *b = &state->b;
b->cursor = nir_after_instr(&intr->instr);
nir_ssa_def *pos = &intr->dest.ssa;
nir_ssa_def *scale = nir_channel(b, get_transform(state), 0);
nir_ssa_def *neg_scale = nir_channel(b, get_transform(state), 2);
/* Either y or 1-y for scale equal to 1 or -1 respectively. */
nir_ssa_def *flipped_y =
nir_fadd(b, nir_fmax(b, neg_scale, nir_imm_float(b, 0.0)),
nir_fmul(b, nir_channel(b, pos, 1), scale));
nir_ssa_def *flipped_pos = nir_vec2(b, nir_channel(b, pos, 0), flipped_y);
nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(flipped_pos),
flipped_pos->parent_instr);
}
static void
swizzle_result(nir_builder *b, nir_tex_instr *tex, const uint8_t swizzle[4])
{
assert(tex->dest.is_ssa);
b->cursor = nir_after_instr(&tex->instr);
nir_ssa_def *swizzled;
if (tex->op == nir_texop_tg4) {
if (swizzle[tex->component] < 4) {
/* This one's easy */
tex->component = swizzle[tex->component];
return;
} else {
swizzled = get_zero_or_one(b, tex->dest_type, swizzle[tex->component]);
}
} else {
assert(nir_tex_instr_dest_size(tex) == 4);
if (swizzle[0] < 4 && swizzle[1] < 4 &&
swizzle[2] < 4 && swizzle[3] < 4) {
unsigned swiz[4] = { swizzle[0], swizzle[1], swizzle[2], swizzle[3] };
/* We have no 0's or 1's, just emit a swizzling MOV */
swizzled = nir_swizzle(b, &tex->dest.ssa, swiz, 4, false);
} else {
nir_ssa_def *srcs[4];
for (unsigned i = 0; i < 4; i++) {
if (swizzle[i] < 4) {
srcs[i] = nir_channel(b, &tex->dest.ssa, swizzle[i]);
} else {
srcs[i] = get_zero_or_one(b, tex->dest_type, swizzle[i]);
}
}
swizzled = nir_vec(b, srcs, 4);
}
}
nir_ssa_def_rewrite_uses_after(&tex->dest.ssa, nir_src_for_ssa(swizzled),
swizzled->parent_instr);
}
static void
lower_load_pointcoord(lower_wpos_ytransform_state *state,
nir_intrinsic_instr *intr)
{
nir_builder *b = &state->b;
b->cursor = nir_after_instr(&intr->instr);
nir_ssa_def *pntc = &intr->dest.ssa;
nir_ssa_def *transform = get_transform(state);
nir_ssa_def *y = nir_channel(b, pntc, 1);
/* The offset is 1 if we're flipping, 0 otherwise. */
nir_ssa_def *offset = nir_fmax(b, nir_channel(b, transform, 2),
nir_imm_float(b, 0.0));
/* Flip the sign of y if we're flipping. */
nir_ssa_def *scaled = nir_fmul(b, y, nir_channel(b, transform, 0));
/* Reassemble the vector. */
nir_ssa_def *flipped_pntc = nir_vec2(b,
nir_channel(b, pntc, 0),
nir_fadd(b, offset, scaled));
nir_ssa_def_rewrite_uses_after(&intr->dest.ssa, nir_src_for_ssa(flipped_pntc),
flipped_pntc->parent_instr);
}
